Resilient chair back mounting



Oct. 3, 1950 CRAMER 2,524,624

RESILIENT CHAIR BACK MOUNTING Filed Aug. 14, 1946 ill ||||mm-I1 INVENTOR.

BY Roy A.Crallzer.

mfgamm/ attorneys Patented Oct. 3, 1950 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to chairs and more particularly to a back rest construction which is capable of tilting movement in opposite directions in order to be automatically adjustable to the back of the user.

In prior chair constructions of the general type having a flexible metal support for the back rest, it has been customary to provide a back rest which is so mounted as to be capable of automatic tilting movement in order to accommodate the back rest to various angles of inclination when the chair is in use. The important feature of the present invention resides in improving and simplifying back rests of this type and while the invention is especially adapted to chairs having a flexible support for the back rest, it is not limited thereto, but may be utilized in connection with other types of chairs, if desired.

One of the objects of the present invention is to provide a novel tiltable back rest which is arranged to materially increase the comfort of the user when the chair is in use.

A further object includes the provision of a back rest including a pair of plates which may be assembled to form a hollow chamber to enable the pivotal mounting of the back rest to be brought closer to the back-engaging portion thereof.

Another object is to provide a novel construction of the above type wherein the parts providing the pivotal mounting are completely housed and hidden from View, thereby presenting a neat and attractive appearance, while protecting the work ing parts from dirt and dust.

Still another object comprehends a novel and simplified back rest construction wherein the pivot pin is mounted in a simple but effective manner, and is positively prevented from accidental displacement after the parts have been assembled.

A still further object includes a novel arrangement of the foregoing character which is capable of economical manufacture and which is so constituted as to be readily and quickly assembled and disassembled with a minimum of efiort.

Other objects and novel features of the invention will appear more fully hereinafter from the following detailed description when taken in connection with the accompanying drawing. It will be expressly understood, however, that the drawing is utilized for purposes of illustration only, and is not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawing, wherein similar reference characters refer to similar parts throughout the several views;

Fig. 1 is a perspective view partly in section of a back rest constructed in accordance with the present invention;

Fig. 2 is a side view in section, of the back rest of Fig. 1;

Fig. 3 is a partial front view of the rear plate and pivotal mounting.

Fig. 4 is a partial perspective view of a detail, certain of the parts being shown in section, and

Fig. 5 is a side view in section of a modified form of back rest.

Referring more particularly to Figs. 1 to 3, the novel back rest construction of the present invention is illustrated therein as including a suitably padded back rest in mounted for tilting or pivotal movement with respect to a sleeve I2, the latter being adapted to be adjustably connected to a back rest support I4 as by means of a hand wheel l6. While the back rest of the present invention may be associated with any suitable type. of support, as shown herein, the support I4 may be of the flexible metal type which is adapted to be fixed to the chair in any desired position of adjustment. Thus when the chair is in use, the support [4 flexes slightly in accordance with the pressure exerted against the back rest Ill, and the latter partakes of an automatic tilting movement with respect to the sleeve l2, in order to secure a comfortable support for the back of the user.

In order to provide th novel tilting construction heretofore referred to, the back rest [0 includes forward and rear plates l8 and 20 which are adapted to be secured together as by a plurality of screws 22 to form a hollow chamber 24 therebetween. As shown, the rear plate 20 is formed with an opening 25, adapted to receive the upper portion 26 of the sleeve 12 and the construction is such that the portion 26 includes a pair of'spaced-apart ears 28 and 30 through which a pivot pin 32 extends, in order to provide a tiltable support for the back rest.

More particularly, the portion of the rear plate 20 defining the opening 25 is provided with a mar-f ginal flange 34 for strengthening purposes, and as shown in Figs. 1 and 3, such flange is formed toprovide a pair of spaced-apart open bearings or supports 36 and 38 for receiving the opposite end portions of the pivot pin 32. With this construction, it will be observed that the assembled plates [8 and 20 are pivotally connected with the ears 2B and 30 of the sleeve l2 in a relatively simple manner, and that the axis of tilt of the back rest is brought closely adjacent the forward plate E8, in order to achieve a more comfortable action in use. Preferably, the forward plate may be provided with spaced slots 46 and 42, to accommodate the forward edges of the ears 28 and 30, and a suitable padding or cushion 44 is applied to the forward face of the plate I8 and maintained in position thereon, as by means of a replaceable cover 46, the margin 48 of which is adapted to receive a draw cord or wire for drawing the cover tightly over the peripheral portion of the plate l8.

One of the features of the present invention resides in a novel arrangement for preventing displacement of the pivot pin 32 after assembly thereof with the plates l8 and 20 and the sleeve [2. In the form of the invention illustrated, such means includes a pair of spaced-apart stops or abutments 58 and 52, see Figs. 2 and 4. Each of these stops is so formed as to include a cutaway portion defining an end stop shoulder 54 and a side bearing surface 58. When the plates I8 and 2.0 are assembled, as shown in Figs. 2 and 4, the side bearing surfaces 56 of the stops 5!! and 52 firmly engage the side of the pivot pin 32 a jacent the end portions thereof in order to maintain the end portions of the latter firmly within the supports 35 and 38. At the same time, the stop shoulders 54 of the stops, engage or are positioned so closely adjacent to the ends of the pivot pin 32 as to prevent any appreciable axial movement of the pin. Thus with the parts assembled as shown, displacement of the pivot pin 32 is positively prevented by the novel stop construction carried by the rear face of the plate l8, and hence a proper relationship of the parts is assured at all times.

A novel arrangement is utilized in the form of the invention shown in Figs. 1-4 inclusive, in order to yieldingly resist tilting movement of the back rest It in either direction with respect to the sleeve l2. As shown, such means comprises a cylindrical member 58, which is preferably formed of rubber so as to be yieldable and deformable, the said member being interposed between the sleeve 12 and a tongue Gil of the rear plate 20.

A pair of threaded parts 62 and 64, are secured to the member 58, in any suitable manner, and the outer ends of such parts are respectively threadedly secured to the sleeve l2 and the tongue 50, as clearly shown in Fig. 2, it being observed from this figure that in normal position, the parts 62 and 6d are aligned and intersect the axis of the pivot pin 32, and that the member 58 is not deformed. It will be clearly understood, however, that when the back rest I is tilted upwardly or downwardly toward the positions illustrated by dotted lines U or D in Fig. 2, the member 58 will be deformed and stretched, and the inherent tendency of the member will be to return the parts to the normal position, as shown in Fig. 2, as soon as the tilting forces are relieved.

While a single resilient member 58 has been shown in Fig. 2 for the purpose of yieldingly resisting tilting movement of the back rest in opposite directions, it will be understood that a pair of resilient members may be utilized, if desired. Fig. shows an arrangement including these latter features, it being observed therefrom, that a pair of springs 66 and 68 are interposed between the respective seats l0 and 12 carried by the sleeve l2, and the tongue 69 of the rear plate 28, one spring 66 being positioned above the pivot pin 32 while the spring 68 is located below the pin. From this construction, it will be readily seen that any tilting movement of the back rest will be yieldingly resisted by one or the other of the springs, which function to normally maintain the parts in the position illustrated.

In assembling the back rest, the upper portion 26 of the sleeve i2 is first projected through the opening in the rear plate 20, after which the pin 32 is passed through the openings in ears 2B and and the end portions of the pin are placed in the supports 36 and 38. At this time, the member 58 is slightly compressed and yieldingly holds the above named parts in position. Thereafter, it is only necessary to attach the front plate l8, to which the cushion and cover have been previously applied, to the rear plate by screws 22, and assemble the back rest upon the support I l at the desired height. In operation of either form of the invention, automatic tilting of the back rest will follow each change of inclination of the back of the user, the member 58, or the springs 66 and 68 always tending to return the back rest to the normal positions shown in Figs. 2 and 5.

It will be noted from Figs. 1 and 2 that the forward back plate 18 is slightly curved in both vertical and horizontal planes, this construction having been found to be more comfortable in use. To further increase the comfort and to avoid back rub when the chair is in use, the present invention provides a construction wherein the vertical center line of the pivot pin 32 is moved as close as possible toward the forward plate l8 and hence toward the back of the occupant. In addition to this latter feature, it has been found in practice, that increased comfort is secured by establishing the horizontal center line of the pivot pin 32 with relation to the height of the rear plate 20. For example, best results have been achieved if the pin 32 is positioned at a distance cf above the bottom of plate 23 which is from .3 to .4 of the height of the plate 20, as measured from the bottom of the plate to the top thereof, as viewed in Fig. 2.

The present invention thus provides a novel back rest construction wherein the pivotal mounting is housed within the chamber defined by the forward and rear plates I8 and 20, and arranged closely adjacent the surface of the back rest which is in contact with the users back. The construction is thus exceedingly comfortable in use and readily follows the variations in the inclination of the back of the user. It will moreover be understood from the foregoing, that the working parts are either housed within the chamber, or hidden from view by the upper portion 26 of the sleeve i2, thereby presenting a neat and attractive appearance, as well as protecting the parts from dirt and dust. Among other features, the use of the stops and 52 serves to automatically maintain the'pivot pin firmly in position, thus avoiding any tendency for the parts to become disassembled in operation.

While two embodiments of the invention have been shown and described herein with considerable particularity, it will be readily understood by those skilled in the art that various changes in the construction of the parts may be resorted to without departing from the spirit of the invention. Reference will therefore be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together" and forming a chamber therebetween, said rear plate having an opening therein, an elongated sleeve adjustably connected with the support and having an upper portion extending through said opening into said chamber, a pair of spaced-apart bearings within the chamber, each of 'said bearings including a part carried by the rear plate and a part carried by the forward plate, a pivot pin mounted in said bearings and pivotally connected with said upper portion of the sleeve, and resilient means interposed between said sleeve and the rear plate for yield: ingly resisting pivotal movement of the plates with respect to the sleeve. A

2. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together and forming a chamber therebetween, said rear plate having an opening therein, an elongated sleeve adjustably connected with the support and having an upper portion extending through said opening and having a pair of spaced apart ears within said chamber, a pair of spaced-apart bearings carried by the rear plate within the chamber, a pivot pin mounted in said bearings and passing through said ears for pivotally connecting the rear plate and sleeve, means carried by the forward plate and engaging opposite ends of said pivot pin when the plates are secured together to prevent displacement of said pin and means interposed between the sleeve and the rear plate for yieldingly resisting pivotal movement of the plates in either direction with respect to the sleeve.

3. A back rest for a chair having an upwardly extending back rest support, comprising a pair of back rest plates adapted to be secured together and forming a chamber therebetween, a hollow sleeve adjustably connected with said support and having its upper portion projecting into said chamber, means within the chamber and including a pivot in for pivotally connecting said upper portion and plates, said means also including a pair of bearings for receiving the ends of the pivot pin, each bearing including a part carried by one plate and a part carried by the other plate, means carried by one of said plates to prevent displacement of said pivot pin when the plates are secured together, and means for yieldingly resisting pivotal movement of the plates in either direction with respect to the sleeve.

4. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together and forming a chamber therebetween, said rear plate having an opening therein, an elongated sleeve adjustably connected with the support and having an upper portion extending through said opening and having a pair of spaced apart ears within said chamber, a pair of spaced-apart supports formed on the rear plate within the chamber, a pivot pin passing through said ears and having its opposite ends mounted in said supports, means carried by the forward plate to engage the side and ends of the pivot pin when the plates are assembled to prevent displacement of the pin, and means interposed between the sleeve and the rear plate for yieldingly resisting pivotal movement of the plates in either direction with respect to the sleeve.

5. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together and forming a chamber therebetween, said rear plate having an openingtheree in, an elongated sleeve adjustablyconnected with the support and having an upper portion extendplate to engage the side of the pin within said supports and to engage the ends of the pin to prevent lateral and axial movement of the pin when the plates are assembled, and a resilient and deformable member connected at one end to the sleeve and at the other end with the rear plate for yieldingly resisting pivotal movement of the plates in either direction with respect to the sleeve.

6. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together and forming a chamber therebetween, said rear plate having an opening therein, an elongated sleeve adjustably connected with the support and having an upper portion extending through said opening and having a pair of spaced apart ears within said chamber, a pair of spaced-apart open supports on the rear plate within the chamber, a pivot pin passing through said ears and having its ends loosely mounted in said open supports, a pair of spaced-apart abutments formed on the rear face of the forward plate to engage the side of the pin within said supports and to engage the ends of the pin to prevent lateral and axial movement of the pin when the plates are assembled, and a pair of springs interposed between the rear plate and the sleeve, one spring being positioned above the pin and the other spring being positioned below the pin, said springs yieldingly resisting pivotal movement of the plates in either direction with respect to the sleeve.

7. A back rest for a chair having an upwardly extending back rest support, comprising a pair of back rest plates secured together and forming a chamber therebetween, a part connected with the support and extending into the chamber through an opening in one of said plates, means including a pivot pin within the chamber for pivotally connecting the part and plates, and an elongated yielding means comprising a resilient and deformable member having its longitudinal axis intersecting the axis of the pivot pin and having one end thereof connected with said part and the other end thereof connected with one of the plates, for yieldingly resisting pivotal movement of the plates in either direction with respect to said part. 7

8. A back rest for a chair having an upwardly extending back rest support, comprising a forward and a rear back rest plate adapted to be secured together and forming a chamber therebetween, said rear plate having an opening therein, and an-elongated sleeve adjustably connected with the support and having an upper portion extending through said opening into said chamber, a pair of spaced-apart bearings carried by the rear plate within the chamber, a pivot pin mounted in said bearings and pivotally connected with said upper portion of the sleeve, and an elongated yielding means comprising a resilient and deformable member having its longitudinal axis,

intersecting the axis of the pivot pin and having one end thereof connected with said sleeve and ROY vA. CRAMER.

- REFERENCES CITED The following references are of record in the 10 file of this patent: 1

Number Number 8 UNITED STATES PA'I'ENTS Name Date Beckman Nov. 29, 1898 Raber Jan. '23, 1917 Zimmerli Dec. 5,- 1922 Johnson et a1 July 1, 1930 Krabol Sept-9, 1930 Johnson Oct. 28, 1930 Gabb Apr. 19, 1938 FOREIGN PATENTS Country Date Germany Jan. 14, 1931 

